Damn, I almost forgot about this thread from yesterday, this one makes me LOL with all of the people here doing this: ::fundy::
Let him prove himself.
Let him prove himself.
My n/a dyno
- Thread starter greensupra_87
- Start date
Ok just got back
got only few good runs in, started raining in the afternoon
this was the best time
going by mph its 182hp to the wheel
by 1/4 mile it's around 190
Does anyone have their 1/4 time and their dyno sheet to compare
got only few good runs in, started raining in the afternoon
this was the best time
going by mph its 182hp to the wheel
by 1/4 mile it's around 190
Does anyone have their 1/4 time and their dyno sheet to compare
starscream5000 said:
I think he may have come close to proving himself. That's certainly a good improvement from a stock N/A.
Nice times, when I was NA, my first run was a 16.5.....then with that run I decided to do the gte swap.
Not too bad. Like I said I don't do 1/4 mile, used to years ago with different cars, too hard on the car, and too expensive to fix. But I'd be interested to see somebody elses slip. Still don't know how you can figure HP by a 1/4 mile slip? I would think there would be even more variables then even a dyno. The same variables as a dyno plus driver reaction, tire pressure, track conditions, so on and so on. Can somebody enlighten me?greensupra_87 said:Ok just got back
got only few good runs in, started raining in the afternoon
this was the best time
going by mph its 182hp to the wheel
by 1/4 mile it's around 190
Does anyone have their 1/4 time and their dyno sheet to compare
Hp=measure of work*(and time)
W=FxD
We know the distance (1/4 mile) and we can determine the force because we know the weight of the car(about as much as a suburban) and how long it took to get there.
F=mass*acceleration
mass=~3500-3600 lbs(maybe)
acceleration => assumed to be constant we would use final velocity / time.
Thats a rough estimate.
You can also use just the final speed and time and not use the distance. but then you have a more indepth integral.
I'm not sure how accurate those hp calculators are because acceleration is obviously not constant in a 1/4 run. the first 250 feet I would think account for a large portion of the total acceleration.
Hope that helps a little
***edit I just looked up some of the hp calculators and they seem to simply use a constant. They take your weight / ((1/4 time)/5.825)^3. Seems like if you took into account the time, final speed AND weight of the car all together and use simple physics like I did, you'd lower the error. :dunno:
Whatever, it's all a rather vague estimate anyways. If the power output of your car was perfectly level, my algorithm would be flawless
**edit again, according to that calculator, a stock turbo supra (16.5 time) only gets 158hp to the wheels :dunno:
W=FxD
We know the distance (1/4 mile) and we can determine the force because we know the weight of the car(about as much as a suburban) and how long it took to get there.
F=mass*acceleration
mass=~3500-3600 lbs(maybe)
acceleration => assumed to be constant we would use final velocity / time.
Thats a rough estimate.
You can also use just the final speed and time and not use the distance. but then you have a more indepth integral.
I'm not sure how accurate those hp calculators are because acceleration is obviously not constant in a 1/4 run. the first 250 feet I would think account for a large portion of the total acceleration.
Hope that helps a little
***edit I just looked up some of the hp calculators and they seem to simply use a constant. They take your weight / ((1/4 time)/5.825)^3. Seems like if you took into account the time, final speed AND weight of the car all together and use simple physics like I did, you'd lower the error. :dunno:
Whatever, it's all a rather vague estimate anyways. If the power output of your car was perfectly level, my algorithm would be flawless
**edit again, according to that calculator, a stock turbo supra (16.5 time) only gets 158hp to the wheels :dunno:
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Thanks. Yes that helps. I believe not as accurate as a dyno due to the variables involved as I mentioned. I guess if you had multi runs to get an average, it could be a little more accurate don't you think? Or at least an average.suprarx7nut said:Hp=measure of work
W=FxD
We know the distance (1/4 mile) and we can determine the force because we know the weight of the car(about as much as a suburban) and how long it took to get there.
F=mass*acceleration
mass=~3500-3600 lbs(maybe)
acceleration => assumed to be constant we would use final velocity / time.
Thats a rough estimate.
You can also use the just the final speed and time and not use the distance. but then you have a more indepth integral.
I'm not sure how accurate those hp calculators are because acceleration is obviously not constant in a 1/4 run. the first 250 feet I would think account for a large portion of the total acceleration.
Hope that helps a little
AJ'S 88NA said:
Well I think the main problem with those calculators is that your peak hp could be a huge spike or a very level bump.
I think using the physics approach i used would give a good idea to your actual, usable, more consistent power output.
To find peak hp i really think the only way is to use a well calibrated dyno and make the appropriate calculations from the torque measured on the dyno.
Honestly, I'd say using an accelerameter, or g-tech meter to measure your 1/4 mile times/speeds and then using that info to figure hp would be the most practical.
The accelerometers should be more accurate because they start the moment you move forward, not when the tree turns.
The gtech meters are supposedly incredibly accurate for 1/4 and 0-60 times.I agree with you on the calibrated dyno. It would elimate a lot of variables in my opinion. I was also curious as to the accuracy of the G-tech meters. I wonder if anybody has compared with a dyno to see how accurate they might be?suprarx7nut said:
gtech claims the following accuracy:
0-60mph: +/- 0.2 mph
1/4 mile +/- 0.01 sec
1/4 mile speed +/- 0.4 mph
Horsepower +/- 1%
Torque and RPM +/- 2%
:aigo:
Plus you can record graphs of your runs, just like a dyno. If you do track days I think this would be incredibly neat. But I'm the kind of dork that analyzes his own gas mileage with agonizing detail
0-60mph: +/- 0.2 mph
1/4 mile +/- 0.01 sec
1/4 mile speed +/- 0.4 mph
Horsepower +/- 1%
Torque and RPM +/- 2%
:aigo:
Plus you can record graphs of your runs, just like a dyno. If you do track days I think this would be incredibly neat. But I'm the kind of dork that analyzes his own gas mileage with agonizing detail
Estimating horsepower from 1/4 mile results is a very poor way of determining how much power you are putting to the wheels. The only formulas I've ever seen for doing this presume a consistent, linear progression from start to finish and they assume the same for the engine's power output.
Then there's the fact that just a different differential can mean big gains or losses in track times (without changing a thing on the engine or the tune).
Accelerometers can be easily rendered inaccurate due to minor miscalculations such as size of gears, tire size/pressure and so on... it depends on how thoroughly thought out the system is and how competent the operator is.
Then there's the fact that just a different differential can mean big gains or losses in track times (without changing a thing on the engine or the tune).
Accelerometers can be easily rendered inaccurate due to minor miscalculations such as size of gears, tire size/pressure and so on... it depends on how thoroughly thought out the system is and how competent the operator is.
Any chance the shortblock has larger pistons? Most rebuilds end up bored out unless they go back to stock specs where the block would have sleeves put back in to get the original bore size and that gets really expensive. Larger displacement could account for some added HP.
way to go green!
you actualy just ran my first time, a 15.3 or what ever in my turbo supra.
i now have it down to 13.5 but every one has to start some where
you actualy just ran my first time, a 15.3 or what ever in my turbo supra.
i now have it down to 13.5 but every one has to start some where
What an.... interesting.... thread. I have a n/a build currently in progress, and was hoping to hit 200+ with a lot of internal work. Guess I'm there already, as I have more done now then he does
I got a lot of internal parts I'm going to sell, since all I got was 17 more hp I'm going to get some of my money back and just go stock:icon_mad:cuel said:What an.... interesting.... thread. I have a n/a build currently in progress, and was hoping to hit 200+ with a lot of internal work. Guess I'm there already, as I have more done now then he does